Some of the most important product attributes are those of product identifiers or IDs.

Many channels require or recommend various product IDs because accurate use of identifiers enables robust, unified product listings.

Identifiers are defined at three levels:

  • Seller
  • Manufacturer
  • Global

Seller identifier

This identifier would be the one most common to sellers, as they typically create their own system for product identification. It goes by different names, but each serves the same purpose, and catalogs use only one seller ID.

This identifier can go by:

  • SKU (Stock Keeping Unit)
  • UID (Unique ID)
  • PID (Product ID)
  • ID

This seller-defined ID isn’t always exactly defined by the seller, though. Sometimes sellers reuse the IDs established by the original vendor. Often, however, sellers create new IDs that are identifiable across their catalog. 

product data seller identifier sku uid pid id format example

Either way, sellers choose how exactly they want each product to be identified across their own catalog. The main point of this ID is for it to be unique across the seller’s catalog.

Product ID best practices:

  • Use a unique ID for each product.
  • Use the same ID when targeting different countries or languages.
  • Don’t use casing to make IDs unique.
  • Don’t reuse the same ID for different products.
  • Avoid white space.

Manufacturer identifier

This next identifier goes beyond the seller but isn’t global yet.

MPN (Manufacturer Part Number) or model number is an identifier assigned by the manufacturer that links the product across distributors, wholesalers, and resellers, back to its source.

Other names for MPN:

  • MN (Model Number)
  • PN, P/N, Part No., Part # (Part Number)

MPNs are most relevant to consumers when they need to repair a device or replace a specific part. In such cases, searching by MPN is a reliable way to find an exact replacement part.

mpn example manufacturer part number
Source: Google

MPN best practices:

  • Major channels use mpn + brand attributes to identify products without a global ID.
  • Use MPN values assigned by the manufacturer.
  • Distinguish between variants.

Global identifiers

Beyond sellers and manufacturers, then we get into global identifiers.

This is what we’re used to seeing on products — what gets scanned at the point of sale at the store, the barcode.


gtin upc ean example barcodes
Source: gtin.info

A barcode represents a string of numbers registered as a GTIN. A product’s GTIN (Global Trade Item Number) is a globally recognized ID that uniquely identifies it across channels and regions.

Types of GTIN:

  • GTIN-8: EAN-8 (European Article Number)
  • GTIN-12: UPC (Universal Product Code)
  • GTIN-13: ISBN (International Book Number), JAN (Japanese Article Number), EAN-13
  • GTIN-14: Wholesale and multipack products

These GTINS are created, indexed, and managed by GS1, a governing body that handles all sorts of global identification numbers.

GS1 standards for identification and standards for barcodes & EPC/RFID
Source: GS1

Whether it’s a UPC, EAN, ISBN, a barcode that goes on a pallet, a box, a case… all of these official identifiers are sold by and registered under GS1.

Check out this example of this GS1 pricing table.

GS1 barcode gtin pricing structure
Source: GS1

Why do my products need GS1 barcodes?

Whether you’re going to sell your products online or in store, the majority of retailers require a UPC. Reputable retailers use GTINS to efficiently identify what your products are and who they belong to.

When you license a GS1 company prefix, you have the capability to create GTINs that identify your company as the brand owner of that product.

It’s like giving your product a fingerprint.

Continue to Product Feed Basics: Data Ecosystems